Explain trigger, Database Management System

Assignment Help:

What is Trigger?

A trigger is a SQL procedure that initiates an action when an event (INSERT, DELETE or UPDATE) occurs. Triggers are kept in and managed by the DBMS. Triggers are used to maintain the referential integrity of data by changing the data in a systematic fashion. A trigger cannot be called or implemented; DBMS automatically fires the trigger as a result of a data modification to the associated table. Triggers can be viewed as same to stored procedures in that both having of procedural logic that is kept at the database level. Stored procedures, though, are not event-drive and are not attached to a specific table as triggers are. Stored procedures are explicitly implemented by invoking a CALL to the procedure whereas triggers are implicitly executed. In addition, triggers can also execute stored procedures.

 


Related Discussions:- Explain trigger

What are the two aspect to the implementation of association, What are the ...

What are the two distinct aspects to the implementation of associations? i) It is required to define data declarations which will enable details of actual links to be stored. I

Define two phase commit, Define Two phase commit Two phase commit: To m...

Define Two phase commit Two phase commit: To make sure atomicity, all the sites where a transaction is being executed must agree on the final outcome of the execution. The tran

Give two profit of reuse of code, Give two profit of Reuse of Code. Re...

Give two profit of Reuse of Code. Reusing the implementation . Place existing class directly inside a new class. The new class can be made up of any number and type of the oth

State the technique for converting a state diagram to code, Q. State the Te...

Q. State the Technique for converting a state diagram to code. i) Identify the major control path. Starting with first state, find the path from diagram that corresponds

Explain growing phase of locking, Explain Growing Phase of locking Grow...

Explain Growing Phase of locking Growing Phase: In this phase the transaction can only obtain locks, but cannot release any lock. The transaction enters the growing phase as so

Define instance and schema, Define instance and schema? Instance: Colle...

Define instance and schema? Instance: Collection of data stored in the data base at a certain moment is Schema: The overall design of the data base is known as the data base

Abap/4 statements to access internal tables without header, What should be ...

What should be declared explicitly in the corresponding ABAP/4 Statements to access internal tables without header lines & why? Work Area. This is needed as the Work Area is

Can you scan double-sided documents and remove blank pages, Can you scan do...

Can you scan double-sided documents - and remove blank pages? Our software and imaging systems supports duplex scanning, at the same time scanning both sides of a page. Program

Define weak and strong entity sets, Define weak and strong entity sets?  ...

Define weak and strong entity sets?  Weak entity  set:  entity  set  that  do not  have  key  attribute  of  their  own are  known as weak entity sets.  Strong entity set

Determine the Disadvantages of file based systems, Determine the Disadvanta...

Determine the Disadvantages of file based systems Some of the disadvantages of file based systems are like this: Data redundancy and inconsistency: the dissimilar applic

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd